Ordinary Londoners leapt into the fray after a man launched a frenzied knife attack on London Bridge on Friday. Brandishing a fire extinguisher and a narwhal tusk, they chased down the fleeing suspect and wrestled him to the ground.
The dramatic confrontation, partially captured in photos and videos by fellow bystanders, drew praise from politicians and members of the public alike, with London Mayor Sadiq Khan lauding the "breathtaking heroism of members of the public who literally ran towards danger".
"They really are the best of us, another example of the bravery and heroism of ordinary Londoners running towards danger, risking their own personal safety to try and save others," he said.
The passers-by "physically intervened to protect the lives of others", said Prime Minister Boris Johnson. "For me, they represent the very best of our country and I thank them on behalf of all of our country."
Witnesses recalled seeing the attacker being pinned to the ground and disarmed by a group of bystanders before police arrived and shot him dead.
Video images showed some people spraying the fleeing suspect with a fire extinguisher, while another passer-by held what appeared to be a long white stick.
Witness Amy Coop said it was a narwhal tusk a man had grabbed off the wall of Fishmongers' Hall - a conference venue to the north end of London Bridge where police officers were called to on Friday afternoon - before going to confront the attacker.
One video posted on social media showed two men struggling on the bridge before police pulled a man in civilian clothes off a black-clad man on the ground. Two gunshots followed, and the man on the ground stopped moving.
Another depicted a man in a suit and overcoat holding a long knife that apparently had been taken from the attacker.
As three officers formed a semi-circle around the suspect, pointing their weapons, it took several seconds before the last man got off him. He was pulled away by one of the armed officers just a split second before another officer fired.
In the videos, a man can be seen retrieving a knife from the huddle on the ground before urging bystanders to get away.
Mr George Robarts, a translator who was on the bridge at the time, said the man had run through traffic and jumped over the central partition to tackle the attacker, along with several other people.
"We ran away but looks like he disarmed him," he said in a tweet. "Amazing bravery."
Tour guide Stevie Hurst, who helped disarm the attacker, said he saw people running away but felt "compelled" to jump out of his car and go towards the incident.
"The guys were just screaming, 'He's stabbed a couple of women'," he told BBC radio.
Recent incidents in Britain
Parliament. A mosque. A pop starlet's concert. And now, once more, London Bridge.
Britain has in the past few years been struck by a series of deadly attacks that have turned a range of targets into sites of terror. Here are some recent incidents:
JUNE 19, 2017
A British man drove a van into Muslim worshippers outside a London mosque, leaving one dead and injuring many more. The man, who was convicted of murder, said at his trial that he had tried to kill as many as possible.
JUNE 3, 2017
Three attackers rammed a van into pedestrians on London Bridge, then stabbed people in nearby bars, killing eight and injuring at least 48 before the police shot all three dead.
The Islamic State in Iraq and Syria said its militants were responsible.
MAY 22, 2017
A suicide bomber killed 22 children and adults and wounded 59 at a packed concert hall in the English city of Manchester, as crowds began to leave a concert by United States singer Ariana Grande.
MARCH 22, 2017
An attacker stabbed a policeman close to the British Parliament in London after a car ploughed into pedestrians on nearby Westminster Bridge. Six people died, including the assailant and the policeman he stabbed, and at least 20 were hurt.
JUNE 16, 2016
Armed with a sawn-off rifle and dagger, a man shot and repeatedly stabbed lawmaker Jo Cox in a frenzied street attack in her constituency in northern England.
MAY 22, 2013
Two attackers drove into and knocked down a British soldier as he crossed a street in broad daylight in south-east London, before killing him with a meat cleaver and knives.
"Everyone was just on top of him trying to bundle him to the ground. I saw that the knife was still in his hand, so I just put a foot in to try and kick him in the head: We were trying to do as much as we could to try and dislodge the knife."
He added: "The guys that were there were just amazing. Absolutely incredible people. Heroes beyond belief."
Mr Hurst said that as the suspect was being pinned down, he was "constantly screaming 'get off me' ", but "we wanted to make sure that he's never going to do this again".
Panic broke out around London Bridge in the moments after the attack.
Mr Rob Underwood, who was visiting London for the day, said he heard bangs that sounded like a firecracker going off and initially did not realise they were gunshots.
"Once you see everybody rushing and scattering, you (are) really fearing for your own safety and I think the major thing was just to get out of the way and get down," the 65-year-old told Reuters.
"You just feel very scared, very anxious about what's happening and just wait for whatever is going on to pass."
Ms Noa Bodner, who was stuck in a restaurant near London Bridge, told BBC News that the manager ran to lock the doors and those sheltering inside had been told to keep away from the windows.
"There was a rush of people coming in, and everybody basically dived under the tables," she said.
Ms Susan Vinn, 57, was outside her office building when she saw people running across the bridge and into her office lobby.
"It's horrible," she said of the attacks that have rattled London in recent years.
"We know it's going to happen again, we just don't know when, so that keeps us worried for sure."
ASSOCIATED PRESS, REUTERS, NYTIMES, AGENCE FRANCE-PRESSE